80 
Journal of Agricultural Research 
Vol. XXIX, No. 2 
clusters of calcium sulphate crystals, 
nodular concretions of iron, marl, and 
surface concentrations of lime or alkali, 
are determined largely by the chemical 
nature of circulating ground waters, by 
overflow, or by the excess of soluble 
salts carried in the mineral subsoils. 
In order to guard against a wrong in¬ 
terpretation of field data, it is neces¬ 
sary to remember, therefore, that 
the chemical nature of the ground- 
water or of the geological formation of 
a region does not in itself determine 
the fertilizer needs of peat land in that 
region. 
The ash of the peat materials, in¬ 
dicated in Table I, consists of the total 
mineral matter left when the organic 
matter is completely burned. The 
differences in ash content range from 
1.07 per cent in the sphagnum peat 
from Calais, Me. to 65.48 per cent in 
the Fremont, Ind., gelatinous material. 
The figures for the three samples of 
bog moss peat, for the Charlevoix, 
Mich., heath shrub and sedge peat, and 
for the Wisconsin reed peat indicate 
that a considerable loss of mineral 
matter has taken place by leaching. 
The sedimentary types of peat, re¬ 
spectively from Fremont, Ind., Mid¬ 
dle River, Calif., and Lake Okeechobee, 
Fla., show a relatively high ash con¬ 
tent; this is to be correlated, un¬ 
doubtedly, with the general siltation of 
the water basins from which these 
samples have been obtained. The ash 
content of the cultivated reed “muck” 
from Plymouth, Ohio, and of the 
drained and aerated woody forest peats 
from Charlevoix, Mich., and Winna- 
mac, Ind., exhibits the influence of 
soil-forming processes; the increase 
during decomposition is due partly to 
the adsorptive power of the finely 
divided organic components, but 
mainly to the transformation of organic 
matter into carbon dioxide. 
Interesting information on the ash 
constituents of plants and peat mate¬ 
rials is reviewed by Hoering (19). 
The recent work of Hibbard (18) indi¬ 
cates that the ash of “tule” (Stirpus la- 
custris var. occidentalis) is similar to 
kainit as a source of potash, but that 
the leached plant remains in the Cali¬ 
fornia tule peat lands have lost most of 
the mineral material worth recovering. 
Miller (81) gives data upon the inor¬ 
ganic composition of sawgrass (Cla- 
dium effusium) from the Florida Ever¬ 
glades. But the evidence submitted 
by him regarding layers of peat sup¬ 
posedly resulting from the accumulation 
of the remains of sawgrass is palpably 
insufficient. The thorough and accu¬ 
rate studies made by Zailer and Wilk 
(58), Bersch (8), Birk (4), and Minssen 
(32) show the changes of the inorganic 
material in different kinds of plants 
forming peat and in the corresponding 
layers of peat derived from them. 
These authors give a large number of 
analyses; they also point out that the 
ash content does not increase with the 
depth of the deposit, but varies with the 
nature of the peat profile, and with the 
contamination by extraneous sand, silt, 
or lime. In general, the work conducted 
by these and other investigators shows 
that silica is undoubtedly one of the 
most stable mineral constituents when 
present in a peat layer, while potash and 
to a less extent, phosphorus leach readily 
from different types of peat. On the 
other hand, it has not been emphasized 
sufficiently that iron and sulphur 
compounds are among those which not 
infrequently affect extensive areas of 
otherwise desirable peat land and may 
cause root rots. The deposition of 
dissolved iron in plant remains and its 
gradual replacement of the organic 
matter has been shown in a former 
publication (8, PL 1). The injurious 
effect of the accumulation of soluble 
iron within the tissues of growing plants 
reported by Sherwin (47) further 
emphasizes the necessity of modifying 
the accepted fertilizer standard of ash 
analyses. 
Continued submersion in water 
makes various mineral salts compara¬ 
tively unstable in peat. The darker 
color of peat samples taken from greater 
depths below the surface, the produc¬ 
tion of sulphuretted hydrogen and of 
methane, the reduction of sulphates 
and possibly of phosphates (vivianite) 
together with those other changes 
which are characterized by the with¬ 
drawal of oxygen not only from the 
water but also from the carbonaceous 
and nitrogenous substances in the 
organic matter, indicate the nature of 
the reduction action (7). The absorp¬ 
tive power for certain mineral sub¬ 
stances appears to be localized in finely 
divided peat. The relative “satura¬ 
tion” of its colloidal constituents prob¬ 
ably influences to a considerable extent 
the character and the varying salinity 
of the peat soil solution, the kind and 
concentration of various bases, and the 
rate at which microorganisms and fila¬ 
mentous fungi decompose peat mate- 
ials. The low mineral salt content of 
certain types of fibrous peat soils in all 
probability accounts for the lack of 
nutrition in the grasses of such peat- 
land pastures. Further work is greatly 
needed to determine the movement, 
absorption, and the losses and exchange 
of soluble mineral material in layers of 
